文献类型：期刊文献

英文题名：Comprehensive Understanding of the Role of Br?nsted and Lewis Acid Sites in Glucose Conversion into 5-Hydromethylfurfural

作者：Li, Xiangcheng[1]; Peng, Kaihao[1]; Liu, Xiaohui[1]; Xia, Qineng[1]; Wang, Yanqin[1]

机构：[1] Shanghai Key Laboratory of Functional Materials Chemistry and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, No. 130 Meilong Road, Shanghai, China

年份：2017

卷号：9

期号：14

起止页码：2739

外文期刊名：ChemCatChem

收录：EI(收录号：20170503319023)

语种：英文

外文关键词：Aluminum oxide - Byproducts - Temperature programmed desorption - Glucose - Niobium compounds - Niobium - Silica - Catalyst selectivity - Alumina - Fourier transform infrared spectroscopy

摘要：The conversion of glucose and selectivity into 5-hydromethylfurfural (HMF) were investigated over various silica–alumina composite (AlSiO) catalysts. The type, amount, and strength of the acidic sites were characterized by using NH3 temperature-programmed desorption and FTIR spectroscopy and then correlated to the catalytic conversion of glucose into HMF to provide a quantitative relationship between the acidity and product selectivity. Lewis acid sites played an important role in glucose conversion, which can enhance the isomerization of glucose to fructose, whereas Br?nsted acid sites had a detrimental effect. HMF selectivity had an almost linear relationship with the weak/total Lewis acid ratio (L*/L), indicating that weak Lewis acids could promote formation of HMF. The medium-to-strong Lewis acid sites can enhance the formation of undesired byproducts (levulinic acid, humins). The Br?nsted to Lewis acid ratio (B/L) had an influence on the HMF selectivity; at similar L*/L ratios, volcano curves were obtained with the increase of the B/L ratio, but the influence was not as great as that of the L*/L ratio. Nb-doped AlSiO catalysts were prepared and used in the conversion of glucose into HMF, which also confirmed the above findings. Under the optimized conditions, the HMF selectivity can reach 71 % at 92.6 % conversion of glucose with no clear decline after four catalytic cycles. ? 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim